1. Field of the Invention
This invention relates to a mown-grass collecting bucket for use as mounted to lawn mowers and, more particularly, to a mown-grass collecting bucket optimum for discharging automatically the grass mown and collected in the bucket.
2. Background of Related Art
The lawn mowers mainly for use on greens in golf courses have been used mostly with the mown-grass collecting bucket mounted to the mowers, due to that the mown grass cannot be left on the green's surface.
It has been necessary for these mowers in which the mown-grass collecting bucket is filled up with the mown grass to dismount the bucket from body structure of the mower and to manually discharge the mown grass out of the bucket.
Generally, the mown-grass collecting bucket weighs about 1.5 to 2.0 kg and the weight reaches about 2.5 to 3.0 kg while it depends on conditions how much the mown grass is wet or moistened. When a larger amount of the mown grass is collected in the bucket and its weight gets larger as a whole, the lawn mower is caused to lean down on the side where the bucket is mounted so as to give an influence on the distance between mowing cutters and the surface of the lawn, so that, in such season as summer in which the lawn grows faster, the mown grass collected in the bucket will have to be discharged quite often, and operators of the lawn mowers are forced to attend to such heavy work.
Various proposals have been made for providing the lawn mower, which is capable of relieving the operator from such heavy work by allowing the mown and collected grass in the bucket to be automatically discharged at a site therefor.
In a grass discharge device or lawn mower disclosed in, for example, Japanese Laid-Open Patent Publication No. 2001-269035, an intake path for the mown grass and including a blower disposed lower part of the mower is changed over to a discharge path from the lower part of grass collecting bucket through the same blower to a high positioned discharge port, in order to have the collected grass discharged while causing stacked grass in the bottom of the bucket to be loosened with an agitator rotated for easier sucking discharge by the blower.
In the case of a grass collecting bucket of lawn mower according to a Japanese Laid-Open Patent Publication No. 2002-65019, the mown grass is carried into the bucket by means of rotating wind of cutter blades, a bottom wall plate of the bucket box-shaped is hinged at its discharge port side edge to allow the other side edge rotated with pressure cylinders so as to compress the collected grass toward the discharge port. In discharging the collected grass, the bucket is lifted with further pressure cylinders and with the discharge port side disposed down, and the port is opened to cause the compressed grass to fall out.
Further, there is disclosed in a Japanese Laid-Open Patent Publication No. 2003-235320 a set of multiple reel mowers, which is provided with mown grass collecting function by mounting a suction cover to respective mowers, connecting discharge ports of these covers through ducts to a suction port of each of blowers disposed on both sides of the operator's seat, and connecting discharge ports of the blowers through ducts to upward opening of a hopper mounted behind the operator's seat, the hopper being tilted with front side lifted by means of cylinders while opening rear side lid for discharging collected mown grass.
In another Japanese Laid-Open Patent Publication No. 2004-265, further, a mown grass discharging device comprises a grass discharge path starting at opposing position of parallel cutter disks rotating in opposite directions and leading through upward blower to a high-position entrance of grass collecting case openable downward, the path having at the starting a slidable bottom plate for allowing any clogging grass discharged downward.
In the case of the foregoing first publication, the discharge of the collected grass from the bottom of the grass collecting bucket to the higher positioned discharge port relies on a suction force of the blower, and there is a risk that the discharge is insufficient while there is provided means for agitating the grass stacked in the bucket. In remaining other cases, too, air stream of the rotating wind of the cutter disks or of the suction force of the blower is employed for carrying the mown grass over a rather long distance from the front side on which the mowing cutter blades are desirably disposed up to the rear upper side on the grass collecting bucket is generally loaded in the mower, and it is required to chose a blower of a larger size or power for sufficient and complete discharge of the mown and collected grass. Further, the grass collecting bucket of a larger size requires the pressure cylinders for the tilting or elevating operation of the bucket, so that the lawn mower will have to be larger in size and complicate in the structure.